18203640 has 128 divisors (see below), whose sum is σ = 67253760. Its totient is φ = 3838464.

The previous prime is 18203639. The next prime is 18203657. The reversal of 18203640 is 4630281.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 18203640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10087 + ... + 11753.

It is an arithmetic number, because the mean of its divisors is an integer number (525420).

Almost surely, 2^18203640 is an apocalyptic number.

18203640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18203640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33626880).

18203640 is an abundant number, since it is smaller than the sum of its proper divisors (49050120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18203640 is a wasteful number, since it uses less digits than its factorization.

18203640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1701 (or 1697 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 18203640 is about 4266.5723947919. The cubic root of 18203640 is about 263.0587463404.

It can be divided in two parts, 1820 and 3640, that added together give a triangular number (5460 = T₁₀₄).

The spelling of 18203640 in words is "eighteen million, two hundred three thousand, six hundred forty".